- #1
Firefox123
- 183
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Question about recoil...
Hey all...
I have a question related to Newtons third law of motion...action and reaction...
I was discussing what happens in certain action/reaction situations like
1. A gun recoiling
2. A rocket flying
3. A balloon filled with air flying after releasing the open end
4. A water hose recoiling from high pressured water
The other person I was speaking with is trying to look at the reaction as a "push" from the exiting air or liquid...
Let me explain...here is how he sees the "rocket" example...
He believes the rocket moves in an upward motion because the expanding gases leaving the bottom of the rocket exert a net upward force on the rocket itself...
since after the gas goes through the opening there isn't any physical contact with the rocket...he sees the gas (or liquid) exerting equal forces in all directions, but since one direction (the opening for any of the 4 examples) is not against the object itself we get a net force.
Im not sure if this is a good way to think about it...
I believe the explanation has something to do with the nature of mass/inertia itself...if some system is losing mass in a certain direction with a certain velocity, then that system must act in such a way to balance that loss of mass.
Am I way off here?
I can't picture any way there could be a physical force transmitted (via the air or water being expelled) to an "edge" or side of a rocket, hose, gun, or balloon in such a way to cause it to move in a direction opposite the flow of the fluid.
Im thinking that we probably shouldn't try to think of it that way and that the answer is more fundamental and has to do with the nature of mass/inertia itself.
Hopefully I haven't completely confused any readers...can anyone help me here?
What really causes the "reaction" in the 4 examples I have listed?
Russ
Hey all...
I have a question related to Newtons third law of motion...action and reaction...
I was discussing what happens in certain action/reaction situations like
1. A gun recoiling
2. A rocket flying
3. A balloon filled with air flying after releasing the open end
4. A water hose recoiling from high pressured water
The other person I was speaking with is trying to look at the reaction as a "push" from the exiting air or liquid...
Let me explain...here is how he sees the "rocket" example...
He believes the rocket moves in an upward motion because the expanding gases leaving the bottom of the rocket exert a net upward force on the rocket itself...
since after the gas goes through the opening there isn't any physical contact with the rocket...he sees the gas (or liquid) exerting equal forces in all directions, but since one direction (the opening for any of the 4 examples) is not against the object itself we get a net force.
Im not sure if this is a good way to think about it...
I believe the explanation has something to do with the nature of mass/inertia itself...if some system is losing mass in a certain direction with a certain velocity, then that system must act in such a way to balance that loss of mass.
Am I way off here?
I can't picture any way there could be a physical force transmitted (via the air or water being expelled) to an "edge" or side of a rocket, hose, gun, or balloon in such a way to cause it to move in a direction opposite the flow of the fluid.
Im thinking that we probably shouldn't try to think of it that way and that the answer is more fundamental and has to do with the nature of mass/inertia itself.
Hopefully I haven't completely confused any readers...can anyone help me here?
What really causes the "reaction" in the 4 examples I have listed?
Russ